PHNOM PENH:— When French commandos boarded the Cambodian-registered freighter Winner in international waters in the Atlantic this month amid an exchange of gunfire that wounded one of the 12 crew members, they seized more than a ton of cocaine in a cargo that was registered as scrap iron destined for Bilbao, Spain.

The unusual high-seas raid — which officials said was the result of a 15-month surveillance operation by U.S., French, Spanish and Greek authorities — exposed the latest in a series of abuses involving ships flying the Cambodian flag.

It was also the most recent sign of increasing U.S., European and Asian government concern over the easy, quick and cheap ship registration systems offered by Cambodia and nearly 30 other mainly developing countries around the world that sanction open registries, or "flags of convenience," as a way of making money.

Critics say that such registries not only contribute to unnecessary loss of life at sea from sinkings and accidents, but also provide cover for criminal and terrorist organizations to smuggle drugs, arms and other illegal cargo.

Under international law, every ship must sail under the flag of a sovereign state to gain the protection of a government while on the high seas and to ensure that safety and other standards are maintained. But to cut costs or evade scrutiny, many shipowners register under foreign flags where fees, taxes, regulations and laws protecting seafarers are often minimal or nonexistent.

A congressional panel in Washington recently began hearings on open registries amid reports that the United States and other North Atlantic Treaty Organization countries were hunting up to 23 ships believed to be controlled by Al Qaeda and operating under flags of convenience. There is also concern terrorists could smuggle a weapon of mass destruction into the United States or another target country via ship as a result of lax rules and checks.

Seafaring unions linked to the International Transport Workers' Federation are urging Congress to enact legislation authorizing the U.S. Coast Guard to refuse entry to American ports to any non-U.S.-flagged ship that does not provide transparency and full identity of the vessel's beneficial owner.

The organization groups nearly 600 transport trade unions in 136 countries representing around 5 million seafarers and other transport workers. It says that the flag-of-convenience system can readily be used to disguise the real owners of ships and is open to exploitation by criminals and terrorists.

In an interview, its general secretary, David Cockroft, called the Cambodian registry — which is based in Singapore, one of the world's busiest seaports — "a sleazy, no-questions-asked operation that has managed to attract some the world's worst ships and owners, some of whom have been involved in people trafficking, drugs smuggling and contraband linked to a terrorist group."

French officials said that the Winner was being escorted by the French Navy to the port of Brest in Brittany, where it would be thoroughly searched.

Meanwhile, police divers are searching for the bodies of two people missing after a small Turkish private ferry was cut in two June 16 by the Modisk 3, a Cambodian-flagged freighter, in Istanbul's Bosporus Strait. Fifteen other passengers, mainly Turkish university students celebrating their graduation, were injured. The captains of both vessels have been held for questioning.

It was the sixth time in 18 months that a Cambodian-registered ship has been involved in a major accident in Turkish waters. In the same period, Cambodian-registered vessels accounted for nearly half of the collisions or groundings involving foreign-flagged ships in Turkish waters, according to figures released by Turkey's Coastal Safety and Salvage Administration.

They have also been involved in serious smuggling cases, at least one of which was reportedly linked to terrorism. In November, Irish customs officers found 20 million smuggled cigarettes on the Maria M, a Cambodian-registered freighter that arrived from Estonia supposedly carrying a cargo of timber. The cigarettes, concealed in the center of bales of timber, were liable to tax amounting to about 3 million Irish punts ($3.7 million)

Anti-terrorist officials said that the operation had been organized by criminals with links to the Real IRA, a terrorist faction opposed to the Northern Ireland peace accord reached with the mainstream Irish Republican Army.

The Winner was boarded by the French commandos 700 miles (1,100 kilometers) southwest of the Canary Islands on June 13. The cocaine it was carrying came from Colombia and had been loaded aboard in the mid-Atlantic on June 4, officials said.

Admiral Jacques Gheerbrant, who headed the French operation to seize the Winner, said the authorities believed that about 2 tons of cocaine had been on board but that crew members had tossed at least a quarter of it overboard before the commandos stopped them.

Two tons of cocaine would have a street value in Europe of €243 million ($235 million), officials estimated

The Cambodian government plans to audit Cambodia Shipping Corp., which runs the Cambodian Shipping Registry and is co-owned by Cambodian, North Korean and Singaporean shareholders.

The Cambodian registry has attracted customers by offering relatively low registration costs and easy Internet access. It has about 450 vessels on its books.

South Korean and U.S. intelligence agencies have been worried for some time about the North Korean connection to Cambodia Shipping through a senior North Korean diplomat who has been stationed in Phnom Penh for many years and was one of the founding investors in the company.

They have also been concerned at the inclusion of North Korean vessels among ships that fly the Cambodian flag. A South Korean analyst said that such ships were suspected of smuggling North Korean ballistic missiles and components to Pakistan, Iran and Iraq.